More than 800,000 viewers on Friday afternoon tuned into Facebook at the same time to watch a live stream of two people placing rubber bands around a watermelon one at a time until it finally exploded.

The numbers spotlighted Facebook’s early success at drawing sizable audiences for appointment viewing as it competes with Snapchat, Twitter’s Periscope and even traditional TV.

Mark Zuckerberg’s social network is making a big push, called Facebook Live, to get its 1.6 billion users to share live footage. Facebook is paying a handful of media companies and some celebrities to stream videos. So far, a live stream by actor Vin Diesel holds the record, at 1 million concurrent views.

“Facebook is trying to find ways to retain users and increase their time with the platform. They’re giving them a reason why they should be checking their timeline as frequently as possible,” said Brian Weiser, a tech analyst for Pivotal.

Discovery Communications, for instance, created a youth-focused science and tech destination for such platforms, called Seeker.

At the same time, there are signs that Facebook is seeing a decline in the amount of detail users share about themselves in their news feeds, a report this week noted.

Total sharing was off 5.5 percent as of midyear 2015, while “original” sharing, or personal posts, were down 21 percent year over year, according to tech blog The Information, which based its report on Facebook’s own confidential data.

Facebook Live could help reverse that trend as people begin broadcasting themselves — although the social network denies there’s cause for concern.

“People continue to share a ton on Facebook; the overall level of sharing has remained not only strong, but similar to levels in prior years,” Facebook said in response.